Electrophilic Substitution Co(II)→M(II) (M = Mn, Ni, Cu, Zn, Cd) in Co2[Fe(CN)6] Gelatin-Immobilized Matrices

Electrophilic substitutions Co(II) → M(II) (M = Mn, Ni, Cu, Zn, Cd) in cobalt(II) hexacyanoferrate(II) gelatin-immobilized matrices in contact with aqueous solutions of corresponding chlorides MCl2 were studied. As a result of this contact, Co(II) was shown to be replaced to some extent by Ni(II), Cu(II), Zn(II), or Cd(II) and to give heteronuclear cobalt(II) hexacyanoferrates(II) and two-charge ions. A complete substitution of Co(II) or the formation the respective mononuclear hexacyanoferrate(II) M2[Fe(CN)2] was observed in neither of the studied systems Co(II) → M(II). No Co(II) → Mn(II) substitution was observed, even though the immobilized matrix was in contact with a solution for a long time.